Apparatus having a wrapped roll for making a single faced corrugated board

Abstract

A single facer containing a first corrugating roll, a second corrugating roll and a gluing mechanism further has an introducing device which is disposed to oppose the second corrugating roll across the liner feed line and pressed against the second corrugating roll via a corrugating medium and a liner; a wrapped roll disposed to oppose the second corrugating roll across the liner feed line on the downstream side of the introducing device with respect to the liner feed direction such that it may not bring the corrugating medium and the liner into press contact with the second corrugating roll, the wrapped roll being driven to rotate at a variable circumferential speed relative to that of the second corrugating roll; a wrapping roll for wrapping the corrugating medium and the liner around the wrapped roll, disposed to oppose the wrapped roll across the feed line, the position of the wrapping roll being adjustable along the circumference of the roll; and a position adjusting mechanism for moving the wrapping roll along the circumference of the wrapped roll so as to change the wrapping area thereon; wherein full adhesion between the corrugating medium and the liner having been subjected to initial adhesion between the second corrugating roll and the introducing device is designed to be achieved by the tension to be generated by the difference between the circumferential speed of the wrapped roll and that of the second corrugating roll.

What is claimed is:  
     
       1. A single facer, comprising 
       a first corrugating roll having wavy flutes formed on the circumference;  
       a second corrugating roll having wavy flutes formed on the circumference to be engageable with the flutes of the first corrugating roll for forming a corrugation on a corrugating medium to be passed between the two rolls;  
       a gluing mechanism for gluing flute tips of the corrugated corrugating medium;  
       introducing means for feeding a liner disposed opposite the second corrugating roll in a line of feeding the corrugating medium and a liner;  
       said introducing means being disposed relative to the second corrugating roll to press the corrugating medium and the liner with a predetermined small nip pressure so that substantially no press marks are formed on the liner;  
       means for supplying heat to at least the circumference of the second corrugating roll;  
       a wrapped roll disposed opposite the second corrugating roll in the line of feeding the corrugating medium and the liner on the downstream side of the introducing means and spaced apart from the second corrugating roll so as not to bring the corrugating medium and the liner into press contact with the second corrugating roll and for wrapping the corrugating medium and the liner over a required wrapping area on the circumference of the second corrugating roll; and  
       position adjusting and control means for moving the wrapped roll with reference to the second corrugating roll depending on feeding speed, type of material or thickness of the corrugating medium and the liner to move the corrugating medium and the liner with respect to the second corrugating roll so that the wrapping area of the corrugating medium and the liner about the circumference of the second corrugating roll is adjusted to achieve a substantially complete bonding of the corrugating medium with the liner.  
     
     
       2. The single facer according to claim  1 , wherein the introducing means is disposed to be able to move closer to or farther from the second corrugating roll via a gap adjusting mechanism, and after a gap to be defined between the opposing portions of the introducing means and the second corrugating roll is adjusted depending on the total thickness of the thickness of the corrugating medium plus the thickness of the liner, the single facer is designed to be operated in a state where the gap between the second corrugating roll and the introducing means is not changed. 
     
     
       3. The single facer according to claim  1 , wherein the wrapped roll is driven to rotate at a speed higher than a circumferential speed of the second corrugating roll so that the corrugating medium and the liner present between the introducing means and the wrapped roll may be brought into press contact with the circumference of the second corrugating roll by the tension generated by the difference between a circumferential speed of the wrapped roll and that of the second corrugating roll. 
     
     
       4. The single facer according to claim  1 ,  2  or  3 , wherein said heat supplying means distributes high-temperature steam into the second corrugating roll to heat the circumference of the second corrugating roll to a predetermined temperature. 
     
     
       5. The single facer according to claim  1 ,  2  or  3 , wherein the introducing means is a roll which is rotated with feeding of the liner. 
     
     
       6. A single facer, comprising first and second corrugating rolls for corrugating a corrugating medium, a roll for pressing a liner against the corrugated corrugating medium with a predetermined small nip pressure so that substantially no press marks are formed on the liner, a gluing mechanism for applying glue to the corrugated corrugating medium or the liner, means for supplying heat to at least the circumference of the second corrugating roll, a wrapped roll spaced apart from the second corrugating roll a distance greater than a thickness of the corrugating medium and the liner and positioned to wrap the corrugating medium and the liner over a wrapping area on the outer surface of the second corrugating roll, and position adjusting means for moving the wrapped roll relative to the second corrugating roll while maintaining the spaced apart distance between the wrapped roll and second corrugating roll to move the liner and the corrugated corrugating medium about a portion of the circumference of the second corrugating roll, said portion defining a wrapping area, including means for adjusting the wrapping area by adjusting the moving of the wrapped roll to achieve substantially complete bonding of the liner and the corrugating medium. 
     
     
       7. The single facer according to claim  6 , wherein the wrapped roll is driven to rotate at a higher speed than the second corrugating roll to generate a tension which presses the corrugating medium and the liner against the outer surface of the second corrugating roll. 
     
     
       8. The single facer according to claim  1 , wherein said position adjusting and control means moves the wrapped roll so as to complete the adhesion between the corrugating medium and the liner over the wrapping area on the circumference of the second corrugating roll. 
     
     
       9. An apparatus for forming a single faced corrugated web from a liner and a corrugating medium comprising: 
       a first corrugating roll having wavy flutes formed on the circumference;  
       a second corrugating roll having wavy flutes formed on the circumference to be engageable with the flutes of the first corrugating roll for forming a corrugation on the corrugating medium to be passed between the two rolls;  
       means for applying a glue adhesive to the exposed flute tips of said corrugated corrugating medium to form adhesive glue lines on said flute tips;  
       means for joining the liner with the corrugated corrugating medium on the second corrugating roll such that the adhesive glue lines are between the liner and said flute tips;  
       means for heating the outer surface of the second corrugating roll to a selected bonding temperature; and  
       means for adjustably wrapping the glued single faced corrugated web around a portion of the circumference of the second corrugating roll downstream of the point of joining the liner with the corrugated corrugating medium sufficient to cause substantially complete bonding of the corrugated corrugating medium with the liner while the glued single faced corrugated web is wrapped around the portion of the second corrugating roll, said portion defining a wrapping area;  
       wherein said means for adjustably wrapping includes means for adjusting the wrapping area to obtain a sufficient amount of heat, at the selected bonding temperature, which is supplied from the outer surface of the second corrugated roll for completely bonding the corrugating medium with the liner.  
     
     
       10. The apparatus as set forth in claim  9  wherein said joining means comprises a rotatable liner roll carrying the liner thereon and forming with the second corrugating roll a nip for said liner and the glued corrugated corrugating medium. 
     
     
       11. The apparatus as set forth in claim  9  wherein the adjustably wrapping means is a wrapping roll. 
     
     
       12. The apparatus as set forth in claim  11  wherein the wrapping roll is a guide roller. 
     
     
       13. The single facer according to claim  11 , wherein the wrapping roll is driven to rotate at a higher speed than the second corrugating roll to generate a tension which presses the corrugating medium and the liner against the outer surface of the second corrugating roll.